Response of Patients with Color Vision Defects to Worth 4-Dot and Duochrome Tests

Background: Individuals with congenital color vision defects (CVDs) are at greater risk of misidentifying colors, necessitating an investigation into their ability to distinguish colors accurately. This study aimed to assess how individuals with CVDs perceive the colors in the Worth four-dot (W4D) and duochrome tests. It also explored whether individuals with CVDs require more detailed instructions from optometrists and eye care providers during these tests. Method: Thirty-two participants with congenital CVDs were recruited for this study. Participants with ocular diseases were excluded based on a brief questionnaire. The participants underwent a W4D test to determine the colors of four circles and the duochrome test without using filters. Result: All the participants correctly identified the W4D colors, except for five participants (15.62%). Furthermore, among all the participants, two (one with deuteranopia and one with protanopia) failed to identify the colors correctly in the duochrome test (6.25%). Conclusions: The findings suggest that in the context of optometric assessment, it could be essential for optometrists to incorporate a preliminary inquiry into a patient's ability to identify colors prior to performing diagnostic tests such as the W4D or duochrome tests. Incorrect responses from patients with CVDs might mislead optometrists regarding the proper outcomes of the test.